Newspaper Rock bed

This geologic dataset covers the area within the boundaries
of Petrified Forest National Park (PEFO), located in
northeastern Arizona (Figure 1) as defined prior to the
expansion approved in December of 2004 (Figure 2); much
of the land in the approved expansion has not yet been
acquired by the National Park Service, and is inaccessible
to the public. The map is based on unpublished mapping by
Billingsley (1985b), Johns (1988), Woody (2003), published
mapping by Martz and Parker (2010), and new mapping.
The geology of the Little Colorado River Valley in
eastern Arizona, including the PEFO area (Figures 1, 2),
is characterized by widespread exposures of Triassic
and Jurassic terrestrial sedimentary rocks. The Upper
Triassic Chinle Formation constitutes the bulk of the
non-Quaternary exposures within the Park (Figure 3).
The Chinle Formation unconformably overlies the Lower-
Middle Triassic Moenkopi Formation. Although this latter
unit is not exposed within PEFO, widespread exposures are
present to the west and south in the Little Colorado River
Valley.

Publication Date

The maps, reports, and other information and content on this website are provided as a public service for informational purposes only. Accuracy is not guaranteed, and the information contained or linked on this website should not be relied on except as general information. The University makes no warranties or representations of any kind, and specifically disclaims all warranties including the warranty of merchantability and fitness for a particular purpose. Users are responsible for verification of all facts and information to their own satisfaction.